The coupling and uncoupling of clutch components within a vehicle's automatic transmission clutch is accomplished by the use of clutch discs and a power transmission member embodied as a clutch hub.
U.S. Pat. No. 3,982,415, issued Sept. 28, 1976 to the same assignee as this invention discloses a machine for splining a power transmission member by rolling. An externally toothed pinion-type mandrel of the machine is rotatably mounted between a pair of elongated die racks. An unsplined member is supported by the mandrel so that sliding movement of the elongated dies from initial end-to-end relationship to an overlapping relationship meshes the teeth on the dies and the teeth on the mandrel with a thinwalled annular sleeve portion of the member therebetween. The meshing of the die and mandrel teeth deforms the sleeve portion of the member radially in a rolling member, forming splines as the mandrel rotates. The die racks each have rough and finish-forming toothed surfaces extending from one end to the other along the face of each die and are driven in opposed direction on either side of the mandrel by a drive train. Opposed synchronizing teeth extend along each die, respectively, for simultaneously forming splines in opposite sides of the blank.
A problem that has arisen from this configuration is the tendency for the finish-forming surfaces to exhibit disproportionately more wear than the rough-forming surfaces, due to the increased stress on the finishing teeth on the die during the latter stages of the spline-forming operation. Consequently, a one-piece die having both the rough and finish-forming surfaces thereon must be entirely reground, or in some instances discarded, although only the finishing surface is worn or cracked due to the strain. Even the unworn finish forming surface must be reground to allow for alignment of the finish forming teeth with the reground rough-forming teeth on the same one piece die. This leads to unnecessary waste and the higher cost associated with replacing an entire one-piece die member.